Protozoa and Helminths

• What microorganisms are listed in the introductory material?

  Water mould, slime mould, protozoa, diatoms, dinoflagellates, algae, green algae
• What are the two main categories of cells discussed in the context of microorganisms?

  Prokaryote and Eukaryote
• According to the provided text, what are the two groups of protists?

  Protozoa and Protophyta
• What are the characteristics that define the following groups: Protozoa, Protophyta and Molds?

  • Protozoa: Heterotrophic/parasitic
  • Protophyta: Autotrophic
  • Molds: Saprophytic
• What are the different types of Protozoa listed?

  • Flagellata
  • Ciliophora
  • Amoeba
  • Sporozoans
• What type of eukaryotic organisms are protozoa?

  Unicellular
• What is a key nutritional characteristic of protozoa?

  Non-photosynthetic
• What characteristic allows protozoa to move?

  Motility
• What type of behavior do protozoa exhibit?

  Animal-like behavior
• What feeding strategy do protozoa use?

  Predation
• What protozoa is larger than 65,000 µm?

  Xenophyophore
• What is the size range of most protozoa?

  10-52µm
• What is the name of the species of Xenophyophore that can measure 200mm?

  Syringammina fragilissima
• Which protozoan species is called ‘First animal’ or ‘little animal’?

  Protozoa
• What are the different habitats in which protozoa can be found?

  • Fresh water
  • Marine water
  • Soil
  • Aerial (trees)
  • Parasitic (animals and humans)
• In what century were protozoa first observed using a microscope?

  17th Century
• What are the alternative names for Giardia duodenalis?

  1. lamblia or G. intestinalis
• Who first observed protozoa?

  Antonie van Leeuwenhoek
• What do protozoa feed on?

  Bacteria/Algae, other protozoa, and larger creatures
• Why are protozoa sometimes referred to as "first animals?"

  They are grazers and hunters
• How do fungi obtain nutrients?

  Absorb through the cell membrane
• What is the function of a vacuole in protozoa?

  To disperse nutrients
• What are the two main stages in the protozoan life cycle?

  • Trophozoites: active, feeding, and motile stage
  • Cysts: dormant, non-motile stage
• What element is found in all protozoa?

  Hydrogen
• What conditions trigger encystation in protozoa?

  Drying, chemicals, and lack of nutrients
• What is the purpose of the cyst stage in the protozoan life cycle?

  To facilitate transmission outside the host
• What is excystation?

  Escape from the cyst
• What are the different forms of reproduction in protozoa?

  • Binary fission
  • Multiple fission
  • Conjugation (sexual genetic exchange, not reproduction)
• What process allows for genetic exchange but not reproduction in protozoa?

  Conjugation
• Why is the classification of protozoa considered problematic?

  Limited genetic data and reliance on characteristics
• What characteristics are traditionally used to classify protozoa?

  • Locomotion
  • Hosts
  • Parasitic species
• What are the different modes of movement in protozoa and their associated groups?

  • Sarcodina: Pseudopodia
  • Mastigophora: Flagella
  • Ciliophora: Cilia
  • Sporozoa: No movement
• In what regions is Entamoeba histolytica most prevalent?

  Developing countries
• What disease is caused by Entamoeba histolytica?

  Parasitic amoeba
• Approximately how many people are infected with Entamoeba histolytica?

  ~50M people
• How is Entamoeba histolytica typically ingested?

  Water, food, or soil contaminated with cysts
• What is the source of contamination for Entamoeba histolytica?

  Faeces
• What are the possible symptoms of Entamoeba histolytica infection?

  Asymptomatic, invasive intestinal amoebiasis, extra-intestinal amoebiasis
• What type of amoebiasis can result in abscesses?

  Invasive extra-intestinal amoebiasis
• What condition is characterized by ulceration and dysentery due to Entamoeba histolytica?

  Invasive intestinal amoebiasis